Here is the full list of all 10 Wordament Snap Attack (Android) achievements worth 50 gamerscore.
You played on a bonus tile
You created your first Multi-Snap
Played all seven tiles in a Multi-Snap
Created a highest scoring snap
You used swap to create a new snap
Play Tap-Snap in more than one language
Make a snap in each of the following shapes
Complete 100 full games
Achieve 2,500,000 total points
Achieved "Sore Fingers" and "Addict" and placed in the top 250 of the “Top Player” leaderboards